Wiring substrate and manufacturing method thereof

ABSTRACT

A wiring substrate includes: a core substrate made of glass and having: a first surface; a second surface opposite to the first surface; and a side surface between the first surface and the second surface; and an insulating layer and a wiring layer, which are formed on at least one of the first surface and the second surface of the core substrate. A plurality of concave portions are formed in the side surface of the core substrate to extend from the first surface to the second surface, and a resin is filled in the respective concave portions.

This application claims priority from Japanese Patent Application No.2012-157907, filed on Jul. 13, 2012, the entire contents of which areherein incorporated by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to a wiring substrate and a manufacturingmethod thereof.

2. Description of the Related Art

In the related art, a wiring substrate for mounting an electroniccomponent such as a semiconductor chip has been known. In the wiringsubstrate, a plurality of interlayer insulating layers and wires areformed on one surface or both surfaces of a core substrate.

As a material of the core substrate, an organic base material, a ceramicbase material, a silicon base material, a glass base material, or thelike may be used. In consideration of a thermal expansion coefficient orinsulation properties, it is preferable that ceramic or glass be used(see e.g., JP-A-2005-86071).

In the related art, it is suggested that glass is used as the materialof the core substrate. However, commercialization of a wiring substrateis not realized which satisfies conditions of an actual product in termsof durability, production yield, productivity, or the like.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a wiring substratecapable of satisfying various conditions as a product in terms ofdurability, production yield, productivity, or the like, and amanufacturing method thereof.

According to one or more aspects of the present invention, there isprovided a wiring substrate. The wiring substrate comprises: a coresubstrate made of glass and comprising: a first surface; a secondsurface opposite to the first surface; and a side surface between thefirst surface and the second surface; and an insulating layer and awiring layer, which are formed on at least one of the first surface andthe second surface of the core substrate. A plurality of concaveportions are formed in the side surface of the core substrate to extendfrom the first surface to the second surface, and a resin is filled inthe respective concave portions.

According to one or more aspects of the present invention, there isprovided a wiring substrate. The wiring substrate comprises: a coresubstrate made of glass and comprising a first surface; a second surfaceopposite to the first surface; and a side surface between the firstsurface and the second surface; and an insulating layer and a wiringlayer, which are formed on at least one of the first surface and thesecond surface of the core substrate. The side surface of the coresubstrate is entirely covered with a resin.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are views showing a wiring substrate according to afirst embodiment;

FIGS. 2A to 2F are process cross-sectional views showing a manufacturingmethod of a wiring substrate according to a first embodiment;

FIG. 3 is a plan view of an opening formation process in themanufacturing method of the wiring substrate according to the firstembodiment;

FIGS. 4A to 4D are process cross-sectional views showing themanufacturing method of the wiring substrate according to the firstembodiment;

FIGS. 5A to 5C are process cross-sectional views showing themanufacturing method of the wiring substrate according to the firstembodiment;

FIGS. 6A to 6C are process cross-sectional views showing themanufacturing method of the wiring substrate according to the firstembodiment;

FIGS. 7A and 7B are process cross-sectional views showing themanufacturing method of the wiring substrate according to the firstembodiment;

FIGS. 8A to 8D are process cross-sectional views showing a firstmodification example of a resin filling process in the manufacturingmethod of the wiring substrate according to the first embodiment;

FIGS. 9A and 9B are process cross-sectional views showing a secondmodification example of the resin filling process in the manufacturingmethod of the wiring substrate according to the first embodiment;

FIGS. 10A to 10E are process cross-sectional views showing a thirdmodification example of the resin filling process in the manufacturingmethod of the wiring substrate according to the first embodiment;

FIGS. 11A and 11B are views showing a first modification example of thewiring substrate of the first embodiment;

FIGS. 12A and 12B are views showing a second modification example of thewiring substrate of the first embodiment;

FIGS. 13A and 13B are views showing a third modification example of thewiring substrate of the first embodiment;

FIGS. 14A and 14B are views showing a fourth modification example of thewiring substrate of the first embodiment;

FIGS. 15A and 15B are views showing a fifth modification example of thewiring substrate of the first embodiment;

FIGS. 16A and 16B are views showing a wiring substrate according to asecond embodiment;

FIGS. 17A to 17D are process cross-sectional views showing amanufacturing method of the wiring substrate according to the secondembodiment;

FIGS. 18A to 18C are process cross-sectional views showing themanufacturing method of the wiring substrate according to the secondembodiment;

FIG. 19 is a plan view in a core substrate disposition process in themanufacturing method of the wiring substrate according to the secondembodiment;

FIGS. 20A to 20C are process cross-sectional views showing themanufacturing method of the wiring substrate according to the secondembodiment;

FIGS. 21A to 21C are process cross-sectional views showing themanufacturing method of the wiring substrate according to the secondembodiment;

FIGS. 22A to 22C are process cross-sectional views showing themanufacturing method of the wiring substrate according to the secondembodiment; and

FIGS. 23A and 23B are process cross-sectional views showing themanufacturing method of the wiring substrate according to the secondembodiment.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present invention will be nowdescribed with reference to the drawings. In each drawing, the samereference numeral is attached to the same component, and the overlappeddescriptions may be omitted.

First Embodiment

(Wiring Substrate)

A wiring substrate according to a first embodiment will be describedwith reference to FIGS. 1A and 1B. FIG. 1A is a plan view in a statewhere a semiconductor chip is mounted on the wiring substrate accordingto the present embodiment, and FIG. 1B is a cross-sectional view takenalong line A-A′ in the plan view of FIG. 1A.

As shown in FIG. 1B, the wiring substrate 10 of the present embodimentincludes a core substrate 12 which is formed of glass. For example, thecore substrate 12 has a thickness of approximately 200 μm. It ispreferable that the thickness of the core substrate 12 be approximately50 μm to 1000 μm.

As the glass which forms the core substrate 12, soda glass, quartzglass, borosilicate glass, alkali-free glass, photosensitive glass, orcrystalline glass may be used.

A plurality of through-electrodes 14 are formed on the core substrate12. For example, the through-electrode 14 has a diameter ofapproximately 50 μm, and is formed of copper.

Insulating layers 16 and wiring layers 18 are alternately formed on bothupper and lower surfaces of the core substrate 12. For example, theinsulating layer 16 has a thickness of approximately 20 μm, and may usea thermosetting epoxy resin, a polyimide resin, an acrylic resin, Teflon(registered trademark) based resin, or the like.

For example, the wiring layers 18 are formed on the insulating layers16, in which openings for connection are formed, by plating copper.

The insulating layers 16 and the wiring layers 18 of the outermostlayers of both upper and lower surfaces of the core substrate 12 arecoated with solder resist layers 20. Openings which reach the wiringlayers 18 are formed in the solder resist layers 20. For example, thesolder resist layer 20 has a thickness of approximately 20 μm.

In the wiring substrate 10 of the present embodiment, a semiconductorchip 28 is mounted on the upper side surface, and the wiring substrate10 is mounted on another substrate (not shown) through the lower sidesurface.

Bumps (connection terminals) 22 for connecting the semiconductor chipare formed on the openings of the solder resist layer 20 of the upperside surface of the wiring substrate 10. Bumps (connection terminals) 24for connecting another substrate (not shown) are formed on the openingsof the solder resist layer 20 of the lower side surface of the wiringsubstrate 10. For example, the bumps (connection terminals) 22 and thebumps (connection terminals) 24 are formed of solder.

The semiconductor chip 28 is mounted on the upper side surface of thewiring substrate 10, and is electrically connected to the wiringsubstrate 10 by bumps (connection terminals) 22. An under-fill resin 26is filled between the wiring substrate 10 and the semiconductor chip 28.

As shown in FIG. 1A, in the wiring substrate 10 of the presentembodiment, side surfaces of the core substrate 12 formed of glass arepartially covered with resins 12 a. Side surfaces of four corners andside surfaces of three locations for each side between the corners inthe core substrate 12 are covered with the resins 12 a.

Three concave portions, which penetrate from the front surface of thecore substrate 12 to the rear surface, are formed on side surfaces ofeach side of the core substrate 12, and the resins 12 a are filled intoeach concave portion. In addition, concave portions, which penetratefrom the front surface of the core substrate 12 to the rear surface, areformed on each corner of the core substrate 12, and the resins 12 a arefilled into each concave portion.

As shown in FIG. 1A, in each side of the core substrate 12, the sidesurfaces of the resins 12 a are flush with the side surfaces of portionswhich are not covered with the resins 12 a.

Moreover, as shown in FIG. 1B, the side surfaces of the wiring substrate10, the side surfaces of the core substrate 12, and the side surfaces ofthe resins 12 a are flush with one another.

For example, a thickness T1 of the thickest portion of the resin 12 a inan in-plane direction of the core substrate 12 is 100 μm. It ispreferable that the thickness T1 be approximately 20 μm to 200 μm.

As the resins 12 a which partially cover the side surfaces of the coresubstrate 12, a thermosetting epoxy resin, a polyimide resin, an acrylicresin, Teflon (registered trademark) based resin, or the like may beused.

In the wiring substrate 10 of the present embodiment, the reason why theside surfaces of the core substrate 12 are partially covered with theresins 12 a will be now described.

A thermal expansion coefficient of glass is approximate to that of thesemiconductor chip mounted on the wiring substrate 12, and the glass hashigh insulation properties. If glass is used for the core substrate, thethermal expansion coefficient of the entire wiring substrate 12 can beapproximate to the thermal expansion coefficient of the semiconductorchip, and stress applied to the semiconductor chip mounted on the wiringsubstrate 12 can be relaxed. In this way, in terms of the thermalexpansion coefficient or the insulation properties, it is preferablethat glass be used as the material of the core substrate.

Therefore, the inventors experimentally prepared the wiring substrateusing the core substrate formed of glass, and the following problemswere found.

First, in order to manufacture a plurality of wiring substrates at onetime, a glass substrate having an area of a plurality of core substrateswas prepared. A plurality of core substrate areas which became the coresubstrate were provided on the glass substrate. Boundaries were setbetween core substrate areas when the glass substrate was separated intorespective core substrates. The boundary was a linear shape having awidth of an approximately cut width of a cutting device, and was set toa lattice shape on the glass substrate.

Subsequently, insulating layers and wiring layers were formed on bothsurfaces of the plurality of core substrate areas of the glasssubstrate. Solder resist layers were coated on the outermost insulatinglayer and wiring layer.

Subsequently, the glass substrate was cut along boundaries by a cuttingdevice, the plurality of core substrate areas were separated, and thewiring substrate was prepared in which insulating layers and wiringlayers were formed on both surfaces of the core substrate formed ofglass.

Subsequently, a temperature cycling test for investigating durability asa product was performed with each wiring substrate.

In this way, the wiring substrate was prepared and the test wasperformed. Then, when the wiring substrate was cut by the cutting deviceor when the temperature cycling test was performed to the wiringsubstrate, many wiring substrates were cracked.

When the cracked wiring substrates were observed, the core substrate waspeeled off vertically in the thickness direction, and the insulatinglayer and the wiring layer were formed on only one surface. Even in thewiring substrates which were not cracked, many fine cracks considered tobe caused due to the cutting of the cutting device were formed on theside surfaces of the core substrates. Particularly, since the cutting bythe cutting device was performed to the corners of the core substratetwice, many cracks were formed on the corners.

In the wiring substrate, the insulating layers and the wiring layers areformed on both surfaces of the core substrate formed of glass. Thethermal expansion coefficient of the insulating layer and the wiringlayer is larger than the thermal expansion coefficient of the coresubstrate formed of glass. If a heat cycle is applied to the wiringsubstrate, stress is applied to the glass substrate due to thedifference of the thermal expansion coefficients. If the cracks areformed on the side surfaces of the core substrate, the core substrate ispeeled off due to the stress which is applied to the core substrate fromthe laminated portion. Due to this phenomenon, it was found that thewiring substrate was cracked.

In the wiring substrate 10 of the present embodiment, the side surfacesof the core substrate 12 are partially covered with the resins 12 a.Since the resins 12 a are flexible, even when the wiring substrate iscut by the cutting device, cracks are not formed on the resins 12 awhich cover the side surfaces of the core substrate 12.

The cracks are formed due to the cutting of the cutting device in theside surfaces of the core substrate 12 which are not covered with theresins 12 a. However, due to the resins 12 a, it is possible to preventthe core substrate 10 from being peeled off

In this way, according to the present embodiment, cracks of the wiringsubstrate are prevented, and durability, production yield, productivity,or the like of the wiring substrate can be improved.

(Manufacturing Method of Wiring Substrate)

A manufacturing method of a wiring substrate according to the firstembodiment will be described with reference to FIGS. 2A to 7B. FIGS. 2Ato 2F and FIGS. 4A to 7B are process cross-sectional views showing themanufacturing method of a wiring substrate according to the firstembodiment, and FIG. 3 is a plan view of an opening formation process inthe manufacturing method of a wiring substrate according to the firstembodiment.

First, a glass substrate 30, which becomes core substrates of aplurality of wiring substrates, is prepared (FIG. 2A).

For example, the glass substrate 30 has a thickness of approximately 200μm. As the glass forming the glass substrate 30 which becomes the coresubstrates, soda glass, quartz glass, borosilicate glass, alkali-freeglass, photosensitive glass, crystalline glass, or the like may be used.

A plurality of core substrate areas, which become core substrates ofwiring substrates, are provided on the glass substrate 30. Boundariesare set between core substrate areas when the glass substrate is dividedinto respective core substrates by the cutting device.

Subsequently, through-electrode openings 32 and resin filling openings34 are formed on the glass substrate 30 (FIG. 2B and FIG. 3). FIG. 2B isa cross-sectional view taken along line B-B′ of the plan view of FIG. 3.

As a method of forming the openings 32 and 34 in the glass substrate 30,there is a method by laser irradiation, a method by laser irradiationand wet etching, a method by electric discharge machining, or the like,and the openings may be formed by any method.

In FIG. 2B, cross-sectional shapes of the openings 32 and 34 arestraight shapes in which the diameters are approximately constant.However, other shapes may be used according to adjustment of the methodof the laser irradiation, the wet etching, the electric dischargemachining, or the like.

FIG. 2C shows a case where the openings 32 and 34 have drum shapes inwhich the diameters of the center portions are decreased. FIG. 2D showsa case where the openings 32 and 34 have taper shapes in which thediameters are gradually decreased. FIG. 2E shows a case where theopenings 32 and 34 have uneven shapes in which the side surfaces of thediameter are uneven.

The shapes of the openings 32 and 34 shown in FIGS. 2C, 2D, and 2E canbe formed by adjustment of the laser irradiation method or bycombination of the laser irradiation and the wet etching. The unevenshapes of the openings 32 and 34 shown in FIG. 2E can be formed by theelectric discharge machining.

In the cases of the drum shapes, the taper shapes, and the uneven shapesshown in FIGS. 2C, 2D, and 2E, as described below, when the resins 12 aare filled in the openings 34, adhesiveness between the resins 12 a andthe inner surfaces of the openings 34 is improved.

Dispositions of the through-electrode openings 32 and the resin fillingopenings 34 formed on the glass substrate 30 will be described withreference to FIG. 3.

A plurality of square core substrate areas AR, which become the coresubstrates of the wiring substrates, are provided on the glass substrate30. Boundaries BD for separating the glass substrate 30 into respectivecore substrates by the cutting device are set between the core substrateareas AR.

As shown in FIG. 3, the resin filling openings 34 are formed on areaswhich include the boundaries BD. One opening 34 is formed at a locationat which the boundaries BD cross each other, and three openings 34 areformed along each side of the square core substrate area AR.

The diameters of the resin filling openings 34 are larger than a width(not shown) of the glass substrate 30 which is removed when the cuttingdevice cuts along the boundaries BD, that is, a width of the cuttingblade of the cutting device. For example, the width of the glasssubstrate 30 which is removed when the cutting device cuts isapproximately 400 μm, and for example, the diameter of the resin fillingopening 34 is 1.5 times or more of approximately 400 μm, that is,approximately 600 μm or more. It is preferable that the diameter of theopening 34 for filling the resin be approximately 450 to 1000 μm.

Thereby, even after the core substrate is cut by the cutting device, theresin filled in the openings 34 remains on the side surfaces of the coresubstrate and covers the side surface.

As shown in FIG. 3, the through-electrode openings 32 are formed in thesquare core substrate area AR. For example, 16 openings 32 of four rowsand four columns are formed.

The diameter of the through-electrode opening 32 is set to anappropriate diameter as the through-electrode which penetrates the coresubstrate, and for example, the diameter is set to 50 μm.

Subsequently, for example, conductive materials including copper arefilled in the through-electrode openings 32 of the glass substrate 30,and thus, through-electrodes 36 are formed (FIG. 2F).

As the method for embedding the conductive materials into the openings32 of the glass substrate 30, there is a plating method, a fillingmethod, or the like, and the embedding may be performed by any method.

For example, electroless plating of copper is performed on the frontsurface of the glass substrate 30 including the inner walls of theopenings 32, and a seed layer is formed. Subsequently, electroplating ofcopper is performed while using the seed layer as a feeding layer, andcopper is filled in the openings 32. Thereafter, the seed layer, whichis exposed from the electroplating layer, is removed, and thethrough-electrodes 36 are formed.

In addition, as shown in FIG. 2F, pads having lager diameters than thoseof the openings 32 are provided on both ends of through-electrodes 36.

Moreover, a wiring layer (wiring pattern), which is connected to thethrough-electrodes 36, may be provided on one surface or both surfacesof the core substrate 30.

Subsequently, resins are filled into the resin filling openings 34 ofthe glass substrate 30. A method for filling the resin into the openings34 will be described in detail with reference to FIGS. 4A to 4D.

First, a resin film 38 is attached to the lower surface of the glasssubstrate 30 (FIG. 4A).

For example, the resin film 38 is formed of a semi-cured (B stage shape)thermosetting resin, and for example, the thickness of the resin film is30 μm. For example, the thermosetting resin is a thermosetting epoxyresin.

Subsequently, if pressure is applied to the glass substrate by an airbag (not shown) while the entire glass substrate is heated in a vacuumchamber (not shown) of a vacuum laminator (not shown), as shown in FIG.4B, the resin film 38 closely contacts the lower surface of the glasssubstrate 30, and the resin is filled to an approximately half from thelower surface in the resin filling openings 34.

Subsequently, a resin film 40 is attached to the upper surface of theglass substrate 30 (FIG. 4C).

For example, the resin film 40 is formed of a semi-cured thermosettingresin, and for example, the thickness of the resin film is 30 μm. Forexample, the thermosetting resin is a thermosetting epoxy resin.

Subsequently, if pressure is applied to the glass substrate by an airbag (not shown) while the entire glass substrate is heated in a vacuumchamber (not shown) of a vacuum laminator, as shown in FIG. 4D, theresin film 40 closely contacts the upper surface of the glass substrate30, and the resin is filled from the upper surface in the resin fillingopenings 34.

Thereafter, the resin films 38 and 40 are cured completely by heatingand become insulating layers 42. As a result, as shown in FIG. 4D, theinsulating layers 42 are formed on both upper and lower surfaces of theglass substrate 30, and resins 42 a are filled in the resin fillingopenings 34. The insulating layers 42 and the resins 42 a are integratedto each other.

Subsequently, openings 42 b, which reach the through-electrodes 36, areformed in the insulating layers 42 formed on both surfaces of the glasssubstrate 30 (FIG. 5A). For example, a method of forming the openings 42b in the insulating layers 42 is performed using laser.

Subsequently, for example, wiring layers 44 including copper are formedon the insulating layers 42 of both surfaces of the glass substrate 30(FIG. 5B). For example, a seed layer (not shown) is formed on theinsulating layer 42, a photoresist layer (not shown) is formed on theseed layer, patterning is performed on the photoresist layer in apredetermined pattern, and the wiring layers 44 having predeterminedpatterns are formed by an electroplating method. Thereafter, thephotoresistor layer is removed, and the seed layer is removed.

Subsequently, for example, resin films (not shown), which are formed ofa semi-cured thermosetting resin, are laminated on the wiring layers 44of both surfaces of the glass substrate 30 and are cured by heating, andthus, insulating layers 46 are formed (FIG. 5C). For example, thethermosetting resin is a thermosetting epoxy resin.

Subsequently, openings, which reach the wiring layers 44, are formed inthe insulating layers 46 of both surfaces of the glass substrate 30. Forexample, a method of forming the openings in the insulating layers 46 isperformed using laser.

Subsequently, for example, wiring layers 48 including copper are formedon the insulating layers 46 of both surfaces of the glass substrate 30(FIG. 5C). For example, the wiring layers 48 are formed according to themethod similar to the wiring layers 44.

Subsequently, insulating layers 50 are formed on the wiring layers 48 ofboth surfaces of the glass substrate 30 (FIG. 5C). For example, theinsulating layers 50 are formed according to the method similar to theinsulating layers 46.

Subsequently, openings, which reach the wiring layers 48, are formed inthe insulating layers 50 of both surfaces of the glass substrate 30. Forexample, a method of forming the openings in the insulating layers 50 isperformed using laser.

Subsequently, for example, wiring layers 52 including copper are formedon the insulating layers 50 of both surfaces of the glass substrate 30(FIG. 5C). For example, the wiring layers 52 are formed by the methodsimilar to the wiring layers 44.

Subsequently, for example, photosensitive solder resist films (notshown) which are formed of an epoxy based resin, an acrylic resin, orthe like, are attached to the wiring layers 52 of both surfaces of theglass substrate 30, and thus, solder resist layers 54 are formed (FIG.6A).

Subsequently, the solder resist layers 54 of the both surfaces of theglass substrate 30 are exposed and developed in a predetermined pattern,and thus, openings 54 a which reach the wiring layers 52 are formed(FIG. 6A).

Subsequently, bumps (connection terminals) 56 for connecting thesemiconductor chip 62 (FIG. 7B) are formed on the wiring layers(electrode pads) 52 which are exposed from the openings 54 a of thesolder resist layer 54 at the upper surface side of the glass substrate30 (FIG. 6B).

Subsequently, bumps (connection terminals) 58 for connecting anothersubstrate (not shown) are formed on the wiring layers (electrode pads)52 which are exposed from openings 54 a of the solder resist layer 54 atthe lower surface side of the glass substrate 30 (FIG. 6C).

For example, the bumps (connection terminals) 56 and the bumps(connection terminals) 58 are formed of solder.

Subsequently, if the structure shown in FIG. 6C is cut by cutting devicealong boundaries BD which pass through approximately centers of theopenings 34 and is divided into a plurality of pieces, a wiringsubstrate 60 shown in FIG. 7A is completed.

Subsequently, the semiconductor chip 62 is mounted on the upper sidesurface of the wiring substrate 60, and an under-fill resin 64 is filledbetween the wiring substrate 60 and the semiconductor chip 62. Thesemiconductor chip 62 is electrically connected to the wiring substrate60 through the bumps (connection terminals) 56.

In this way, according to the present embodiment, it is possible tomanufacture the wiring substrate in which durability, production yield,productivity, or the like is improved.

(Modification Example of Method of Filling Resin into Opening of GlassSubstrate)

In the above-described embodiment, according to the resin filling methodshown in FIGS. 4A to 4D, the resins are filled into the resin fillingopenings 34 of the glass substrate 30. However, the present invention isnot limited to the method, and other methods may be used.

Modification examples of the resin filling method which fills resinsinto the resin filling openings 34 of the glass substrate 30 will bedescribed with reference to FIGS. 8A to 10E.

(First Modification Example)

A first modification example of the resin filling method of the openingsof the glass substrate will be described with reference to FIGS. 8A to8D.

First, a resin film 70 is attached to the lower surface of the glasssubstrate 30 (FIG. 8A).

For example, the resin film 70 is formed of a semi-cured thermosettingresin, and for example, the thickness of the resin film is 30 μm. Forexample, the thermosetting resin is a thermosetting epoxy resin.

Subsequently, if strong pressure is applied to the glass substrate by anair bag (not shown) while the entire glass substrate is heated in avacuum chamber (not shown) of a vacuum laminator, as shown in FIG. 8B,the resin film 70 closely contacts the lower surface of the glasssubstrate 30, and the resin is filled completely full in resin fillingopenings 34 from the lower surface.

Subsequently, a resin film 72 is attached to the upper surface of theglass substrate 30 (FIG. 8C). Thereafter, the resin films 70 and 72 arecured completely by heating and become insulating layers 42.

As a result, as shown in FIG. 8D, the insulating layers 42 are formed onboth upper and lower surfaces of the glass substrate 30, and the resins42 a are filled in the entire resin filling openings 34. The insulatinglayers 42 and the resins 42 a are integrated to each other.

Thereafter, the wiring substrate 60 is formed by the method shown inFIGS. 5A to 7B.

(Second Modification Example)

A second modification example of the resin filling method of theopenings of the glass substrate will be described with reference toFIGS. 9A and 9B.

First, resin films 74 and 76 are attached to both upper and lowersurfaces of the glass substrate 30 (FIG. 9A).

For example, the resin films 74 and 76 are formed of a semi-curedthermosetting resin, and for example, the thicknesses of the resin filmsare 30 μm. For example, the thermosetting resin is a thermosetting epoxyresin.

Subsequently, if strong pressure is applied to the glass substrate by anair bag (not shown) while the entire glass substrate is heated in avacuum chamber (not shown) of a vacuum laminator, as shown in FIG. 9B,the resin films 74 and 76 closely contact both upper and lower surfacesof the glass substrate 30, and the resins are entirely filled in resinfilling openings 34 from both upper and lower surfaces. Thereafter, theresin films 74 and 76 are cured completely by heating and becomeinsulating layers 42.

As a result, as shown in FIG. 9B, the insulating layers 42 are formed onboth upper and lower surfaces of the glass substrate 30, and the resins42 a are entirely filled in the resin filling openings 34. Theinsulating layers 42 and the resins 42 a are integrated to each other.

Thereafter, the wiring substrate 60 is formed by the method shown inFIGS. 5A to 7B.

(Third Modification Example)

A third modification example of the resin filling method of the openingsof the glass substrate will be described with reference to FIGS. 10A to10E.

First, an adhesive tape 78, which can be easily peeled off, is attachedto the lower surface of the glass substrate 30, and the bottom of theresin filling openings 34 is closed (FIG. 10A).

Subsequently, a liquid or paste-like resin 80 is supplied to the uppersurface of the glass substrate 30, and a squeegee 82 is operated undervacuum atmosphere (FIG. 10A).

A height of the squeegee 82 is adjusted so that only a predeterminedheight is positioned above the upper surface of the glass substrate 30.If the squeegee 82 is operated, the resin 80 is pushed into the resinfilling openings 34 to a certain degree.

For example, as the resin 80, a thermosetting resin such as an epoxyresin, an acrylic resin, a polyimide resin, or a silicone resin is used.

Subsequently, if atmospheric pressure is increased, the resin 80 isreached to the bottom of the resin filling openings 34 due to differenceof air pressure in the resin filling openings 34 (FIG. 10B).

Subsequently, a scraper 84 is moved along the upper surface of the glasssurface 30, and the resin 80 remaining on the upper surface of the glasssubstrate 30 is removed (FIG. 10C). Thereafter, the resin 80 is curedcompletely by heating.

Subsequently, the adhesive tape 78 attached to the lower surface of theglass substrate 30 is peeled off (FIG. 10D).

In this way, the resin 80 is filled into the resin filling openings 34of the glass substrate 30.

Subsequently, insulating layers 42 are formed on both upper and lowersurfaces of the glass substrate 30 (FIG. 10E).

Thereafter, the wiring substrate 60 is formed by the method shown inFIGS. 5A to 7B.

(Modification Example of Location of Through-Electrode Opening and ResinFilling Opening)

In the above-described embodiment, the through-electrode openings 32 andthe resin filling openings 34 are formed on the glass substrate 30 asshown in FIG. 3. As a result, as shown in FIG. 1A, the wiring substrate10, in which side surfaces of the core substrate 12 formed of glass arepartially covered with the resins 12 a, is manufactured. However, thepresent invention is not limited to this location and other locationsmay be used.

Modification examples of locations of the through-electrode openings 32and the resin filling openings 34, which are formed on the glasssubstrate 30, will be described with reference to FIGS. 11A to 15B.

(First Modification Example)

A first modification example of the location of the through-electrodeopenings 32 and the resin filling openings 34, which are formed on theglass substrate 30, will be described with reference to FIGS. 11A and11B. FIG. 11A corresponds to FIG. 3 and FIG. 11A is a plan view showingthe location of the through-electrode openings 32 and the resin fillingopenings 34, and FIG. 11B corresponds to FIG. 1A and FIG. 11B is a planview of the wiring substrate 10. The same reference numerals areattached to the same elements as those of FIGS. 1A and 3, and theoverlapped descriptions are omitted herein.

In the present modification example, the resin filling openings 34 areformed only at locations at which boundaries BD cross each other.

The plurality of square core substrate areas AR, which become the coresubstrates of the wiring substrates, are provided on the glass substrate30. Boundaries BD for dividing the glass substrate 30 into respectivecore substrates by the cutting device are set between the core substrateareas AR.

As shown in FIG. 11A, the resin filling openings 34 are formed atlocations at which boundaries BD cross each other.

The diameters of the resin filling openings 34 are larger than a widthof the glass substrate 30 which is removed when the cutting device cutsalong the boundaries BD, that is, a width of the cutting blade of thecutting device. Thereby, even after the core substrate is cut by thecutting device, the resin filled in the openings 34 remains on the sidesurfaces of the core substrate and cover the side surface.

As shown in FIG. 11A, the through-electrode openings 32 are formed inthe square core substrate area AR. For example, 16 openings 32 of fourrows and four columns are formed.

As shown in FIG. 11B, in the wiring substrate 10 of the firstmodification example, the side surfaces of the core substrate 12 formedof glass are partially covered with the resins 12 a. The side surfacesof four corners of the core substrate 12 are covered with the resins 12a.

In this way, according to the present modification, since side surfacesof the corners of the core substrate are covered with resin, cracks ofthe wiring substrate are prevented, and thus, durability, productionyield, productivity, or the like of the wiring substrate can beimproved.

(Second Modification Example)

A second modification example of the location of the through-electrodeopenings 32 and the resin filling openings 34, which are formed throughthe glass substrate 30, will be described with reference to FIGS. 12Aand 12B. FIG. 12A corresponds to FIG. 3 and FIG. 12A is a plan viewshowing the location of the through-electrode openings 32 and the resinfilling openings 34, and FIG. 12B corresponds to FIG. 1A and FIG. 12B isa plan view of the wiring substrate 10. The same reference numerals aregiven to the same elements as those of FIGS. 1A and 3, and theoverlapped descriptions are omitted herein.

In the present modification example, the resin filling openings 34 areformed at locations at which boundaries BD cross each other and on theareas along each side of the core substrate area AR.

The plurality of square core substrate areas AR, which become the coresubstrates of the wiring substrates, are provided on the glass substrate30. Boundaries BD for dividing the glass substrate 30 into respectivecore substrates by the cutting device are set between the core substrateareas AR.

As shown in FIG. 12A, in the resin filling openings 34, circularopenings 34A are formed at locations in which boundaries BD cross eachother, and elongated openings 34B are formed on areas along each side ofthe core substrate area AR.

The diameters of the circular openings 34A are larger than the widthwhich is removed when the cutting device cuts along the boundaries BD,that is, the width of the cutting blade of the cutting device.

The widths of the elongated openings 34B are larger than the width ofthe glass substrate 30 which is removed when the cutting device cutsalong the boundaries BD, that is, the width of the cutting blade of thecutting device.

As shown in FIG. 12A, the through-electrode openings 32 are formed inthe square core substrate area AR. For example, 16 openings 32 of fourrows and four columns are formed.

As shown in FIG. 12B, in the wiring substrate 10 of the secondmodification example, the side surfaces of the core substrate 12 formedof glass are partially covered with the resins 12 a and 12 b. The sidesurfaces of four corners of the core substrate 12 are covered with theresins 12 a, and the side surfaces of each side between corners of thecore substrate 12 are covered with the resins 12 b.

In this way, according to the present modification example, since theside surfaces of the corners and the side surfaces of each side of thecore substrate are covered with resins, the cracks of the wiringsubstrate are more securely prevented, and thus, durability, productionyield, productivity, or the like of the wiring substrate can beimproved.

(Third Modification Example)

A third modification example of the disposition of the through-electrodeopenings 32 and the resin filling openings 34, which are formed throughthe glass substrate 30, will be described with reference to FIGS. 13Aand 13B. FIG. 13A corresponds to FIG. 3 and FIG. 13A is a plan viewshowing the location of the through-electrode openings 32 and the resinfilling openings 34, and FIG. 13B corresponds to FIG. 1A and FIG. 13B isa plan view of the wiring substrate 10. The same reference numerals aregiven to the same members as those of FIGS. 1A and 3, and the overlappeddescriptions are omitted herein.

In the present modification example, the resin filling openings 34 areformed at sides near locations at which boundaries BD cross each otherand on the areas along each side of the core substrate area AR.

The plurality of square core substrate areas AR, which become the coresubstrates of the wiring substrates, are provided on the glass substrate30. Boundaries BD for dividing the glass substrate 30 into respectivecore substrates by the cutting device are set between the core substrateareas AR.

As shown in FIG. 13A, in the resin filling openings 34, cross-shapedopenings 34C are formed at locations in which boundaries BD cross eachother, and elongated openings 34D are formed on areas along each side ofthe core substrate area AR.

The widths of the cross-shaped openings 34C are larger than the width ofthe glass substrate 30 which is removed when the cutting device cutsalong the boundaries BD, that is, the width of the cutting blade of thecutting device.

The widths of the elongated openings 34D are larger than the width ofthe glass substrate 30 which is removed when the cutting device cutsalong the boundaries BD, that is, the width of the cutting blade of thecutting device.

As shown in FIG. 13A, the through-electrode openings 32 are formed inthe square core substrate area AR. For example, 16 openings 32 of fourrows and four columns are formed.

As shown in FIG. 13B, in the wiring substrate 10 of the thirdmodification example, four corners and the side surfaces near thecorners of the core substrate 12 formed of glass are covered with theresins 12 c, and the side surfaces of each side between corners of thecore substrate 12 are covered with resins 12 d.

In this way, according to the present modification example, since thecorners, the side surfaces near the corners, and the side surfaces ofeach side of the core substrate are covered with resins, the cracks ofthe wiring substrate are more securely prevented, and thus, durability,production yield, productivity, or the like of the wiring substrate canbe improved.

(Fourth Modification Example)

A fourth modification example of the location of the through-electrodeopenings 32 and the resin filling openings 34, which are formed throughthe glass substrate 30, will be described with reference to FIGS. 14Aand 14B. FIG. 14A corresponds to FIG. 3 and FIG. 14A is a plan viewshowing the disposition of the through-electrode openings 32 and theresin filling openings 34, and FIG. 14B corresponds to FIG. 1A and FIG.14B is a plan view of the wiring substrate 10. The same referencenumerals are given to the same members as those of FIGS. 1A and 3, andthe overlapped descriptions are omitted herein.

In the present modification example, in addition to the areas includingthe boundaries BD in the embodiment of FIGS. 1A and 3, the resin fillingopenings are also formed on areas adjacent to the boundaries BD.

The plurality of square core substrate areas AR, which become the coresubstrates of the wiring substrates, are provided on the glass substrate30. Boundaries BD for dividing the glass substrate 30 into respectivecore substrates by the cutting device are set between the core substrateareas AR.

As shown in FIG. 14A, in the resin filling openings 34, circularopenings 34A are formed at locations in which boundaries BD cross eachother and on areas along each side of the core substrate area AR.Moreover, in the areas adjacent to the boundaries BD, circular openings34E are formed between the circular openings 34A. That is, the circularopenings 34E are formed near the locations at which the openings 34A arenot formed on each side of the core substrate area AR.

The diameters of the circular openings 34A formed on areas including theboundaries BD are larger than the width of the glass substrate 30 whichis removed when the cutting device cuts along the boundaries BD, thatis, the width of the cutting blade of the cutting device.

As shown in FIG. 14A, it is preferable that the circular openings 34Eformed on areas adjacent to the boundaries BD be positionedapproximately in the middle of the circular openings 34A formed on areasincluding boundaries BD. The diameters of the circular openings 34E maybe larger than the width of the cutting blade of the cutting device.

As shown in FIG. 14A, the through-electrode openings 32 are formed inthe square core substrate area AR. For example, 9 openings 32 of threerows and three columns are formed.

As shown in FIG. 14B, in the wiring substrate 10 of the fourthmodification example, the side surfaces of the core substrate 12 formedof glass are partially covered with the resins 12 a. The side surfacesof four corners and the side surfaces of three locations of each sidebetween corners of the core substrate 12 are covered with the resins 12a. Moreover, in areas adjacent to the side surfaces of the coresubstrate 12, resins 12 e are embedded between the resins 12 a of theside surfaces.

In this way, according to the present modification example, since thecorners and the side surfaces of each side of the core substrate arecovered with resins, the cracks of the wiring substrate are prevented,and thus, durability, production yield, productivity, or the like of thewiring substrate can be improved. In addition, since the resins 12 e areembedded between the resins 12 a of the side surfaces of the coresubstrate 12, breakage of the cracks of the side surfaces which are notcovered with the resins 12 a of the core substrate 12 can be preventedby the resins 12 e.

(Fifth Modification Example)

A fifth modification example of the disposition of the through-electrodeopenings 32 and the resin filling openings 34, which are formed throughthe glass substrate 30, will be described with reference to FIGS. 15Aand 15B. FIG. 15A corresponds to FIG. 3 and FIG. 15A is a plan viewshowing the location of the through-electrode openings 32 and the resinfilling openings 34, and FIG. 15B corresponds to FIG. 1A and FIG. 15B isa plan view of the wiring substrate 10. The same reference numerals aregiven to the same members as those of FIGS. 1A and 3, and the overlappeddescriptions are omitted herein.

In the present modification example, in addition to the sides includinglocations at which boundaries BD cross each other and areas along eachside of the core substrate area AR, the resin filling openings are alsoformed on areas adjacent to the boundaries BD.

The plurality of square core substrate areas AR, which become the coresubstrates of the wiring substrates, are provided on the glass substrate30. Boundaries BD for dividing the glass substrate 30 into respectivecore substrates by the cutting device are set between the core substrateareas AR.

As shown in FIG. 15A, in the resin filling openings 34, cross-shapedopenings 34C are formed at locations in which boundaries BD cross eachother, and elongated openings 34D are formed on areas along each side ofthe core substrate area AR. Moreover, in the areas adjacent to theboundaries BD, elongated openings 34F are formed between cross-shapedopenings 34C and elongated openings 34D. That is, the elongated openings34F are formed near the locations at which openings 34C and 34D are notformed in each side of the core substrate area AR.

The widths of the cross-shaped openings 34C are larger than the width ofthe glass substrate 30 which is removed when the cutting device cutsalong the boundaries BD, that is, the width of the cutting blade of thecutting device.

The widths of the elongated openings 34D are larger than the width ofthe glass substrate 30 which is removed when the cutting device cutsalong the boundaries BD, that is, the width of the cutting blade of thecutting device.

As shown in FIG. 15A, it is preferable that the elongated opening 34Fformed on areas adjacent to the boundaries BD be positioned between thecross-shaped openings 34C and the elongated openings 34D. The widths ofthe elongated openings 34F may be larger than the width of the cuttingblade of the cutting device.

As shown in FIG. 15A, the through-electrode openings 32 are formed inthe square core substrate area AR which is partitioned by the boundariesBD. For example, 16 openings 32 of four rows and four columns areformed.

As shown in FIG. 15B, in the wiring substrate 10 of the fifthmodification example, the four corners and the side surfaces near thecorners of the core substrate 12 formed of glass are covered with theresins 12 c, and the side surfaces of each side between corners of thecore substrate 12 are covered with resins 12 d. In addition, in theareas adjacent to the side surfaces of the core substrate 12, resins 12f are embedded between the resins 12 c and the resins 12 d of the sidesurfaces.

In this way, according to the present modification example, since thecorners, the side surfaces near the corners, and the side surfaces ofeach side of the core substrate are covered with resins, the cracks ofthe wiring substrate are prevented, and thus, durability, productionyield, productivity, or the like of the wiring substrate can beimproved. In addition, since the resins 12 f are embedded between theresins 12 c and the resins 12 d of the side surfaces of the coresubstrate 12, breakage of the cracks of the side surfaces which are notcovered with the resins of the core substrate 12 can be prevented by theresins 12 f.

Second Embodiment

(Wiring Substrate)

A wiring substrate according to a second embodiment will be describedwith reference to FIGS. 16A and 16B. FIG. 16A is a plan view in a statewhere a semiconductor chip is mounted on the wiring substrate accordingto the present embodiment, and FIG. 16B is a cross-sectional view takenalong line C-C′ in the plan view of FIG. 16A.

As shown in FIG. 16B, a wiring substrate 110 of the present embodimentincludes a core substrate 112 which is formed of glass. For example, thecore substrate 112 has a thickness of approximately 200 μm.

As the glass which forms the core substrate 112, soda glass, quartzglass, borosilicate glass, alkali-free glass, photosensitive glass,crystalline glass, or the like may be used.

A plurality of through-electrodes 114 are formed on the core substrate112. For example, the through-electrode 114 has a diameter ofapproximately 50 μm, and is formed of copper.

Insulating layers 116 and wiring layers 118 are alternately formed onboth upper and lower surfaces of the core substrate 112. For example,the insulating layer 116 has a thickness of approximately 30 μm and isformed of an epoxy based resin. For example, the wiring layers 118 areformed on the insulating layers 116, in which openings for connectionare formed, by plating copper.

The insulating layers 116 and the wiring layers 118 of the outermostlayers of both upper and lower surfaces of the core substrate 112 arecoated with solder resist layers 120. Openings which reach the wiringlayers 118 are formed in the solder resist layers 120. For example, thesolder resist layer 120 has a thickness of approximately 20 μm.

In the wiring substrate 110 of the present embodiment, a semiconductorchip 128 is mounted on the upper side surface, and the wiring substrateis mounted on another substrate (not shown) through the lower sidesurface.

Bumps (connection terminals) 122 for connecting the semiconductor chip128 are formed in the openings of the solder resist layer 120 of theupper side surface of the wiring substrate 110. Bumps (connectionterminals) 124 for connecting another substrate (not shown) are formedin the openings of the solder resist layer 120 of the lower side surfaceof the wiring substrate 110.

The semiconductor chip 128 is mounted on the upper side surface of thewiring substrate 110, and is electrically connected to the wiringsubstrate by bumps (connection terminals) 122. An under-fill resin 126is filled between the wiring substrate 110 and the semiconductor chip128.

As shown in FIG. 16A, in the wiring substrate 110 of the presentembodiment, all side surfaces of the core substrate 112 formed of glassare covered with resins 112 a.

For example, a thickness T2 of the resin 112 a in an in-plane directionof the core substrate 112 is 100 μm. It is preferable that the thicknessT2 be approximately 20 μm to 200 μm.

As the resins 112 a which cover the side surfaces of the core substrate112, a thermosetting epoxy resin, a polyimide resin, an acrylic resin,Teflon (registered trademark) based resin, or the like may be used.

As shown in FIG. 16B, in each side of the wiring substrate 110, the sidesurfaces of the insulating layers 116 and the side surfaces of theresins 112 a exposed to the side surfaces of the wiring substrate 110are formed so as to be flush with each other.

In the wiring substrate 110 of the present embodiment, since all sidesurfaces of the core substrate 112 are covered with the resins 112 a,cracks from the side surfaces of the core substrate 10 can be prevented.

In this way, according to the present embodiment, cracks of the wiringsubstrate are prevented, and durability, production yield, productivity,or the like of the wiring substrate can be improved.

(Manufacturing Method of Wiring Substrate)

A manufacturing method of a wiring substrate according to a secondembodiment will be described with reference to FIGS. 17A to 23B. FIGS.17A to 17D, FIGS. 18A to 18C, and FIGS. 20A to 23B are processcross-sectional views showing the manufacturing method of a wiringsubstrate according to the second embodiment, and FIG. 19 is a plan viewof a core substrate alignment process in the manufacturing method of awiring substrate according to the second embodiment.

First, a glass substrate 130, which becomes core substrates of aplurality of wiring substrates, is prepared (FIG. 17A).

For example, the glass substrate 130 has a thickness of approximately200 μm. As the glass forming the glass substrate 130 which becomes thecore substrates, soda glass, quartz glass, borosilicate glass,alkali-free glass, photosensitive glass, crystalline glass, or the likemay be used.

A plurality of square core substrate areas AR, which become coresubstrates of wiring substrates, are provided on the glass substrate130. Boundaries BD for dividing the glass substrate 130 into respectivecore substrates by the cutting device are set between the core substrateareas AR.

Subsequently, in the glass substrate 130, the through-electrode openings132 are formed in each core substrate area AR (FIG. 17B). The diameterof the through-electrode opening 132 is set to an appropriate diameteras the through-electrode which penetrates the core substrate, and forexample, the diameter is set to 50 μm.

As a method of forming the openings 132 in the glass substrate 130,there is a method by laser irradiation, a method by laser irradiationand wet etching, a method by electric discharge machining, or the like,and the openings may be formed by any method.

In FIG. 17B, cross-sectional shapes of the openings 132 are straightshapes in which the diameters are approximately constant. However, othershapes may be used according to adjustment of the method of the laserirradiation, the wet etching, the electric discharge machining, or thelike.

For example, the openings may be formed in drum shapes in whichdiameters of the center portions are decreased as shown in FIG. 2C,taper shapes in which the diameters are gradually decreased as shown inFIG. 2D, and uneven shapes in which the side surfaces of the diameterare uneven as shown in FIG. 2E.

Subsequently, for example, conductive materials including copper arefilled in the through-electrode openings 132 of the glass substrate 130,and thus, through-electrodes 136 are formed (FIG. 17C). As the methodfor filling the conductive materials into the openings 132 of the glasssubstrate 130, there is a plating method, a filling method, or the like,and the embedding may be performed by any method.

In addition, as shown in FIG. 17C, pads having lager diameters thanthose of the openings 132 are provided on both ends ofthrough-electrodes 136. Moreover, a wiring layer (wiring pattern), whichis connected to the through-electrodes 136, may be provided on onesurface or both surfaces of the core substrate 130.

Subsequently, if the glass substrate 130, on which thethrough-electrodes 136 are formed, is cut along boundaries BD by thecutting device and is divided into a plurality of pieces, and theplurality of core substrates 112 are formed (FIG. 17D).

If the glass substrate 130 is cut by the cutting device, cracks areformed on the side surfaces of the core substrate 112. However, as shownin FIGS. 17C and 17D, since insulating layers or wiring layers are notformed on both surfaces of the glass substrate 130, shrinkage force orthe like is not applied from the outside, and the core substrate 112 isnot cracked.

Subsequently, in a state where the plurality of core substrates 112formed as described above are arranged with predetermined intervals, allthe core substrates are embedded with resins. A method of embedding thecore substrate 112 with resins will be described.

First, a support 140 which has sufficient dimensions for mounting theplurality of core substrates 112, and a resin film (insulating sheet)142 for temporarily attaching to the plurality of core substrates 112are prepared (FIG. 18A).

For example, the support 140 has a thickness of approximately 100 μm andis formed of copper. Predetermined alignment marks AM are formed on thesupport 140. By using the alignment marks AM, the resin film (insulatingsheet) 142 can be disposed at a predetermined position, and the coresubstrate 112 can be arranged with predetermined intervals.

For example, the resin film (insulating sheet) 142 has a thickness ofapproximately 30 μm, and is formed of a thermosetting epoxy resin. Thecore substrate 112 can be temporarily fixed in a semi-cured state by theadhesive force of the resin film.

Subsequently, the resin film (insulating sheet) 142 is provided on thesupport 140 (FIG. 18B). The resin film 142 is fixed to the support 140by the adhesive force of the resin film (insulating sheet) 142.

Subsequently, by using the alignment marks AM formed on the support 140,the plurality of core substrates 112 are arranged on the resin film(insulating plate) 142 at predetermined positions with predeterminedintervals, and are temporarily attached to the resin film 142 (FIG.18C). For example, the predetermined interval between the coresubstrates 112 is 600 μm.

FIG. 19 is a plan view in a state where the resin film (insulatingplate) 142 is disposed on the support 140, and the plurality of coresubstrates 112 are disposed on the resin film (insulating plate) 142 andare temporarily attached to the resin film 142. The plurality of coresubstrates 112 are disposed on the resin film (insulating plate) 142with predetermined intervals by using alignment marks AM of the support140.

Subsequently, a resin film (insulating plate) 144 for covering theplurality of core substrates 112 from the upper portion is prepared(FIG. 20A). For example, the resin film (insulating plate) 144 has athickness of approximately 600 μm and is formed of a semi-curedthermosetting resin. For example, the thermosetting resin is athermosetting epoxy resin.

Subsequently, the resin film (insulating plate) 144 is attached onto theplurality of core substrates 112 (FIG. 20B).

Subsequently, if pressure is applied to all the core substrates by anair bag (not shown) while all the core substrates are heated in a vacuumchamber (not shown) of a vacuum laminator, the resin films (insulatingplates) 142 and 144 closely contact both surfaces of the plurality ofcore substrates 112, and are filled between the plurality of coresubstrates 112.

Thereafter, the resin films 142 and 144 are cured completely by heatingand become insulating layers 146. As a result, as shown in FIG. 20C, theinsulating layers 146 are formed on both upper and lower surfaces of theplurality of core substrates 112, and an insulating material 146 a isfilled between the plurality of core substrates 112. The insulatinglayers 146 and the resin 146 a are integrated to each other.

Subsequently, for example, the support 140 formed of copper is removedby etching (FIG. 21A).

Subsequently, openings 146 b, which reach the through-electrodes 136,are formed in the insulating layers 146 formed on both surfaces of theplurality of core substrates 112 (FIG. 21B). For example, a method offorming the openings 146 b on the insulating layers 146 is performedusing laser.

Subsequently, for example, wiring layers 148 including copper are formedon the insulating layers 146 of both surfaces of the plurality of coresubstrates 112 (FIG. 21C). For example, a seed layer (not shown) isformed on the insulating layer 146, a photoresist layer (not shown) isformed on the seed layer, a predetermined patterning is performed on thephotoresist layer, and the wiring layers 148 having predeterminedpatterns are formed by an electroplating method. Thereafter, thephotoresistor layer is removed, and the seed layer is removed.

Subsequently, for example, resin films (not shown), which are formed ofa semi-cured thermosetting resin, are attached to the wiring layers 148of both surfaces of the plurality of core substrates 112 and are curedby heating, and thus, insulating layers 150 are formed (FIG. 22A). Forexample, the thermosetting resin is a thermosetting epoxy resin.

Subsequently, openings, which reach the wiring layers 148, are formed onthe insulating layers 150 of both surfaces of the plurality of coresubstrates 112. For example, a method of forming the openings on theinsulating layers 150 is performed using laser.

Subsequently, for example, wiring layers 152 including copper are formedon the insulating layers 150 of both surfaces of the plurality of coresubstrates 112 (FIG. 22A). For example, the wiring layers 152 are formedaccording to the method similar to the wiring layers 148.

Subsequently, insulating layers 154 are formed on the wiring layers 152of both surfaces of the plurality of core substrates 112 (FIG. 22A). Forexample, the insulating layers 154 are formed according to the methodsimilar to the insulating layers 150.

Subsequently, openings, which reach the wiring layers 152, are formed onthe insulating layers 154 of both surfaces of the plurality of coresubstrates 112. For example, a method of forming the openings in theinsulating layers 154 is performed using laser.

Subsequently, for example, wiring layers 156 including copper are formedon the insulating layers 154 of both surfaces of the plurality of coresubstrates 112 (FIG. 22A). For example, the wiring layers 156 are formedby the method similar to the wiring layers 148.

Subsequently, for example, photosensitive solder resist films (notshown), which are formed of an epoxy based resin, an acrylic resin, orthe like, are attached to the wiring layers 156 of both surfaces of theplurality of core substrates 112, and thus, solder resist layers 158 areformed (FIG. 22A).

Subsequently, the solder resist layers 158 of the both surfaces of theplurality of core substrates 112 are exposed and developed in apredetermined pattern, and thus, openings 158 a which reach the wiringlayers 156 are formed (FIG. 22A).

Subsequently, bumps (connection terminals) 160 for connecting thesemiconductor chip are formed on the wiring layers (electrode pads) 156which are exposed from the openings 158 a of the solder resist layer 158of the upper surface side of the plurality of substrates 112 (FIG. 22B).

Subsequently, bumps (connection terminals) 162 for connecting anothersubstrate are formed on the wiring layers (electrode pads) 156 which areexposed from openings 158 a of the solder resist layer 158 of the lowersurface side of the plurality of core substrates 112 (FIG. 22C).

For example, the bumps (connection terminals) 160 and the bumps(connection terminals) 162 are formed of solder.

Subsequently, if a multilayered wiring structure shown in FIG. 22C iscut by a cutting device along boundaries BD and is divided into aplurality of pieces, a wiring substrate 170 shown in FIG. 23A iscompleted.

Subsequently, a semiconductor chip 172 is mounted on the upper sidesurface of the wiring substrate 170, and under-fill resin 174 is filledbetween the wiring substrate 170 and the semiconductor chip 172. Thesemiconductor chip 172 is electrically connected to the wiring substrate170 through the bumps (connection terminals) 160.

In this way, according to the present embodiment, it is possible tomanufacture the wiring substrate in which durability, production yield,productivity, or the like is improved.

(Modification Example of Method for Embedding Core Substrate with Resin)

In the embodiment, according to the method shown in FIGS. 18A to 20C,all core substrates 112 are embedded with resins in the state where theplurality of core substrates 112 are arranged with predeterminedintervals, and the resins are filled between the plurality of coresubstrates 112. However, the present invention is not limited to thismethod, and other methods may be applied.

For example, the resin film (insulating sheet) is disposed on a supportportion such as a placement stage without using the support, and theplurality of core substrates are disposed on the resin film (insulatingsheet). The plurality of core substrates are covered with the resin film(resin sheet), and the resins are filled between the plurality of coresubstrates.

Modified Embodiment

The above-described embodiments are an example, and variousmodifications can be performed if necessary.

For example, in the above-described embodiments, the insulating layersand the wiring layers are formed on both surfaces of the core substrate,and thus, the wiring substrate is manufactured. However, the insulatinglayers and the wiring layers may be formed on only one surface of thecore substrate. Moreover, the number of the insulating layers and thewiring layers, which are formed on the wiring substrate, is not limitedto the number described in the above-described embodiments, and thenumber of the layers may not be limited.

Moreover, in the above-described embodiments, the bumps (connectionterminals) are formed on the wiring substrate. However, the bumps maynot be formed if necessary.

Various aspects of the subject-matter described herein are set outnon-exhaustively in the following numbered clauses:

1. A method of manufacturing a wiring substrate, the method comprising:

(a) providing a glass substrate comprising a plurality of core substrateareas each corresponding to one of core substrates;

(b) forming a plurality of openings through the glass substrate along aboundary line between the respective core substrate areas;

(c) filling a resin into the respective openings;

(d) forming an insulating layer and a wiring layer on the glasssubstrate; and

(e) dividing the glass substrate into a plurality of the core substratesby cutting the glass substrate along the boundary line, therebyobtaining a plurality of the wiring substrates.

2. The method according to clause 1,

wherein the step (c) comprises:

(c-1) providing a resin sheet on the glass substrate; and

(c-2) pressing the resin sheet against the glass substrate so as to filla portion of the resin sheet into the respective openings.

3. The method according to clause 2, wherein in the step (b), at leastsome of the openings are formed at respective cross points of theboundary line.

4. The method according to clause 3, wherein the step (b) comprisesforming another openings through the glass substrate, and the step (c)comprises filling the resin into the respective another openings.

5. A method of manufacturing a wiring substrate comprising:

(a) disposing a first resin sheet on a support;

(b) disposing a plurality of core substrates on the first resin sheetwith a certain interval, wherein the core substrates are made of glass;

(c) covering the core substrates with a second resin sheet so as to fillgaps between the adjacent core substrates with a resin;

(d) forming an insulating layer and a wiring layer on the coresubstrates;

(e) cutting the resin filled in the gaps between the adjacent coresubstrates such that the core substrates are separated from each other,thereby obtaining a plurality of the wiring substrate.

As described above, the preferred embodiment and the modifications aredescribed in detail. However, the present invention is not limited tothe above-described embodiment and the modifications, and variousmodifications and replacements are applied to the above-describedembodiment and the modifications without departing from the scope ofclaims.

What is claimed is:
 1. A wiring substrate comprising: a core substratemade of glass and comprising: a first surface; a second surface oppositeto the first surface; and a side surface between the first surface andthe second surface; and an insulating layer and a wiring layer, whichare formed on at least one of the first surface and the second surfaceof the core substrate, wherein a plurality of concave portions aredefined in the side surface of the core substrate, each of the pluralityof concave portions continuously extending from the first surface to thesecond surface, and a resin is filled in each of the plurality ofconcave portions.
 2. The wiring substrate according to claim 1, whereina surface of the resin filled in the concave portions is substantiallyflush with the side surface of the core substrate.
 3. The wiringsubstrate according to claim 1, wherein at least some of the concaveportions are located at respective corners of the core substrate.
 4. Awiring substrate comprising: a core substrate made of glass andcomprising a first surface; a second surface opposite to the firstsurface; and a side surface between the first surface and the secondsurface; and an insulating layer and a wiring layer, which are formed onat least one of the first surface and the second surface of the coresubstrate, wherein the side surface of the core substrate is entirelycovered with a resin, the resin projecting from the side surface of thecore substrate and including an outer surface that is spaced from theside surface of the core substrate.
 5. The wiring substrate according toclaim 1, wherein the resin filled in the respective concave portions isintegrally formed with the insulating layer.
 6. The wiring substrateaccording to claim 4, wherein the resin entirely covering the sidesurface of the core substrate is integrally formed with the insulatinglayer.
 7. The wiring substrate according to claim 1, wherein theinsulating layer and the wiring layer are formed on both of the firstsurface and the second surface of the core substrate, wherein theinsulating layer comprises: a first insulating layer on the firstsurface; and a second insulating layer on the second surface, whereinthe wiring layer comprises: a first wiring layer on the first surface;and a second wiring layer on the second surface, wherein the resinfilled in the respective concave portions is integrally formed with thefirst insulating layer and the second insulating layer.
 8. The wiringsubstrate according to claim 4, wherein the insulating layer and thewiring layer are formed on both of the first surface and the secondsurface of the core substrate, wherein the insulating layer comprises: afirst insulating layer on the first surface; and a second insulatinglayer on the second surface, wherein the wiring layer comprises: a firstwiring layer on the first surface; and a second wiring layer on thesecond surface, wherein the resin entirely covering the side surface ofthe core substrate is integrally formed with the first insulating layerand the second insulating layer.
 9. The wiring substrate according toclaim 1, wherein the core substrate has an opening formed therethrough,and a resin is filled in the opening.
 10. The wiring substrate accordingto claim 1, wherein the side surface of the core substrate defines atleast a first portion of a side surface of the wiring substrate, and theresin defines at least a second portion of the side surface of thewiring substrate.
 11. The wiring substrate according to claim 1, whereineach of the plurality of concave portions linearly extends along theside surface from the first surface to the second surface.
 12. Thewiring substrate according to claim 11, wherein each of the plurality ofconcave portions is defined in the first surface and the second surface.13. A wiring substrate comprising: a core substrate made of glass andcomprising: a first surface; a second surface opposite to the firstsurface; and a side surface between the first surface and the secondsurface; and an insulating layer and a wiring layer, which are formed onat least one of the first surface and the second surface of the coresubstrate, wherein a plurality of concave portions are defined in theside surface of the core substrate, each of the plurality of concaveportions extending from the first surface to the second surface, and aresin is filled in each of the plurality of concave portions, andwherein each of the plurality of concave portions is defined in thefirst surface and the second surface.
 14. The wiring substrate accordingto claim 4, wherein a thickness of the resin covering the side surfaceof the core substrate is between 20 μm to 200 μm, and the outer surfaceof the resin is spaced between 20 μm to 200 μm from the side surface ofthe core substrate.
 15. The wiring substrate according to claim 4,wherein side surfaces of the insulating layer are flush with sidesurfaces of the resin covering the side surface of the core substrate.16. The wiring substrate according to claim 15, wherein a thickness ofthe resin covering the side surface of the core substrate is between 20μm to 200 μm, and the outer surface of the resin is spaced between 20 μmto 200 μm from the side surface of the core substrate.